Aldehyde scavengers for photographic silver halide developers



United States Patent 3,141,771 ALDEHYDE SCAVENGERS FOR PHOTOGRAPHIC SILVER HALIDE DEVELOPERS Charleton C. Bard and Deane S. Thomas, Rochester, N.Y.,

assignors to Eastman Kodak Company, Rochester,

N.Y., a corporation of New Jersey No Drawing. Filed Feb. 1, 1961, Ser. No. 86,288 13 Claims. (Cl. 96--22) This invention relates to photography, and more particularly, photographic developers for use in reversal processing of photographic color films and papers.

In mul-ti-layer photographic elements used for color photography, there are usually three selectively sensitive emulsion layers coated on one side of a photographic support. For example, the uppermost layer is generally bluesensitive, the next layer generally comprises a yellow filter, and the next layer is generally green-sensitive. The emulsion layer adjacent to the support is generally red-sensitive. The yellow filter layer located between the blueand green-sensitive layers serves to absorb the blue radiation which may be transmitted through the blue-sensitive layer to the underlying layers, which are sensitive to the blue region of the spectrum, in addition to the red or green regions of the spectrum. Sometimes such multilayer photographic elements contain additional silver halide emulsion layers or other interlayers for specialized purposes. In photographic print materials, frequently the yellow filter layer is omitted and the arrangement of silver halide emulsion layers may be changed for the purpose of obtaining more accurate recording of the color negative. Multi-layer materials of the type which can be used in the present invention have been previously described in the prior art, such as Mannes et al. US. Patent 2,252,718, issued August 19, 1941.

Color materials of the type employed in the present invention include those which are intended primarily for reversal color processes, in which the exposed material is given a conventional black-and-white negative development, followed by a reversal exposure, or exposures, and finally color development. The color materials useful in our invention include those having a silver halide emulsion containing the color-forming materials or couplers in the emulsion, as well as color materials which are intended for processing in a color developer which contains the color couplers.

It is, therefore, an object of our invention to provide improved developers for reversal color photography. Another object is to provide a method of removing aldehydes whose presence is not desired in the developers used for processing reversal color materials. Other objects will become apparent from a consideration of the following examples and description.

In the processing of photographic color materials by a reversal technique in which the color couplers are incorporated in the color developers, it is rather common practice to use a balancing developing agent in one or more of the color developers. This practice is particularly common with respect to the cyan color developer. Such balancing developers serve two functions, in general. First, such balancing developers act as antioxidants and they frequently react with oxidized color developer through a cross-oxidation reaction, which regenerates the desired color developer. Secondly, such balancing developing agents react directly with the exposed silver halide as an auxiliary developer. The desired photographic effects of these balancing developing agents in the cyan color developer are (1) scooped out red toe, (2) increased red speed, (3) the overall red contrast increases and (4) ice the inherent high definition of the cyan color developer is not appreciably reduced.

However, certain balancing developing agents which fill the above requirements do have adverse effects in the reversal color developers customarily employed, in that they frequently react with the silver halide to produce oxidized balancing developers and metallic silver. In addition, these balancing developing agents can react with oxidized color developing agent generating a Schiifs base, which latter ingredient undergoes rather rapid hydrolysis in the strongly alkaline color developers to produce free aldehyde. While some reduction of the silver halide by the balancing developer may be desired in certain color processes where it is desired to completely reduce all exposed silver halide, so that no unreduced silver halide remains in one emulsion layer before proceeding with exposure and development of another emulsion layer, the formation of Schiifs bases in color developers is particularly objectionable, since such Schifis bases are so easily hydrolyzed to free aldehydes. These free aldehydes can react with some of the color developing agent, which causes the formation of objectionable impurities in the color developer.

Balancing developing agents which are particularly useful, but which have the objectionable property of forming Schiifs bases, include compounds embraced by the following general formula:

wherein R represents an aralkyl group, such as benzyl, which may or may not contain additional substituents, such as hydroxyl, amino, nitro, chloro, bromo, alkyl (e.g., methyl, ethyl, etc.), etc., and R represents a p-hydroxyphenyl group which can be further substituted by lower alkyl groups, such as methyl, ethyl, etc. Balancing developing agents which are particularly useful and are embraced by Formula I above, include the following:

wherein R represents a monocyclic aryl group of the benzene series, such as phenyl, hydroxyphenyl, chlorophenyl, aminophenyl, sulfophenyl (including alkali metal salts thereof, such as sodium and potassium), tolyl, ethylphenyl, etc.

We have found that the undesirable effects of these balancing developing agents in color developers can be largely or entirely overcome, without adversely affecting their desirable properties, by including a primary amine which has a hydroxyl, carbonyl, or amino (substituted or not) group attached to the primary amine radical, in the color developer. Typical amines, which can be used in the form of their free base, or more conveniently in the form of their acid addition salts (e.g., hydrochloride, sulfate, phosphate, etc.) include semicarbazide, hydrazine, carbohydrazide, hydroxylamine, etc. These compounds and others which can be used in our invention, can be represented by the following formulas:

H2NOH hydroxylamine HzNNH C NHz semicarbazide hydrazine HzNN 11 3 NHNH oarbohydrazide HZNNHNHQ biuret I NH" 2% HENNH NHz aminoguanidine H2NNHONHCH3 methylsemicarbazide Girards reagent Amines which are particularly useful in our invention are those which have little or no reducing action toward silver halide of their own, such as semicarbazide and carbohydrazide.

The amines useful in practicing our invention can be utilized in various concentrations, depending upon the concentration of balancing developer used, the concentration of color developer, etc. In general, we have found that from'about 0.1 to about 5.0 grams per liter of amine are satisfactory for the purposes of our invention. It is apparent that small amounts of amine can be used in those cases where the amine has some undesired developing or solvent action of its own toward silver halide, such "as is the case for hydrazine and its salts. In the case of those amines which have little or no developing or solvent action of their own toward silver halide, larger amounts can be easily tolerated without having any adverse effects upon the color development. The most advantageous concentration can be determined by developing a series of test strips of silver halide emulsions wherein the concentration of the amine, as well as the concentration of the developing agent, is varied. The usual addenda can be employed in the developers, such 'as strongly alkaline agents (e.g., sodium carbonate, potassium carbonate, sodium hydroxide, etc.), restraining agents, such as potassium bromide or iodide, stain preventatives and antioxidants, such as alkali metal sulfites, etc.

Our invention is primarily directed to the development .of the ordinarily employed gelatino-silver-halide developing-out emulsions, e.g., gelatino-silver-chloride, -chlorobromide, -chloroiodide, -chlorobromiodide, -bromide and .-bromiodide developing-out emulsions. While the results in the following examples were obtained using gelatinosilver-bromiodide emulsions, excellent results can also be obtained using other silver halide emulsions. These emulsions can be coated in the usual manner on any suitable support, e.g., glass, cellulose nitrate film, cellulose ester film, polyvinyl acetal resin film, paper or metal. Photographic silver halide emulsions useful in our invention can also contain such addenda as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamide, thiourea, allyl isothiocyanate, cystine, etc.), various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.) (see U.S. Patents 2,540,085; 2,597,856 and 2,597,915), various azaindene compounds (such as those disclosed in U.S. Patent 2,716,062), condensation products of alkylene oxides, such as those shown in U.S. Patent 2,400,032, as well as the additives mentioned in Jones et al. U.S. Patent 2,937,089.

The advantages of our invention are particularly outstanding in reversal color photographic processes wherein the color-forming compounds, or couplers, are incorporated in the color developing baths. The advantages of our invention are also outstanding in reversal color processes where a color film containing couplers in the emulsions (or alternatively in the color developers) has been given a hardening treatment in a bath prior to development (color or black-and-white) so that development can be performed at a higher temperature and in a shorter period of time. Such hardening prebaths generally contain an aldehyde hardener, such as formaldehyde or succinaldehyde. Even where the photographic material has been given a washing treatment between the prebath and the developer, it has not been possible to remove sufficient aldehyde to avoid many of the adverse photographic eifects resulting from the use of the aldehyde hardener in the prcbath. According to our invention, one of the above-identified amines can also be incorporated in a black-and-white or color negative developer to avoid the undesirable effects of the free aldehyde. The free aldehyde has alparticularly undesirable efiect in development of the color image in that it spontaneously reacts with the coupler (e.g., magenta or yellow) by an irreversible reaction, thereby causing a loss of color density.

The pH ofthe developers useful in our process, including both the colordevelopers and the black-and-white negative developers, can be varied, depending upon the particular material which is to be processed therein. In

the case of color developers, it has been found that particularly useful results can be obtained where the pH is relatively high, i.e., at least 10.0 and preferably about 11.5.

It is possible to employ these developers at even higher pI-Is, such as 12.5 to equal advantage.

Typical. color-forming compounds or, couplers which are. useful in color. photography, according to our invention, include the following:

COUPLERS PRODUCING CYAN IMAGES ,6 {'y {4 42,4 di-tert. amylphenoxy)butyramido] phenoxy}acetamido}-2,4-dichloro-3-methylphenol 1 hydroxy 2 [6.- (2,4 di tert. amylphenoxy) nbutyHnaphthamide 2 (p tert. amylphenoxy) n butyrylamino 4 chloro- S-mcthylphenol 2-(p tert. amylphenoxy p benzoyl)amino 4 chloro- S-methylphenol 2 4" i tert. amyl 3' phenoxybenzoylamino) 3,5-dimethyll-phenol V 2-phenylacetylamino-4-chloro-5-methylphenol 2-benzoylamino-4-chloro-S-methylphenol 2-anilinoacetylamino-4-chloro-S-methylphenol' '2 {4' [a (4 tert; amylphenoxy) n butyrylamino] benzoylamino}-4-chloro-5-methylphenol 2 [4,3" (4 tert. amylphenoxy)benzoylamino]benzoylamino-4-chloro-S-methylphenol 2-p-nitrobenzoylamino-4-chloro-S-methylphenol 2-m-aminobenzoyl 4-chloro-5-methylphenol o-{ 3 [u- (2,4-di-tert.-amylphenoxy) butyramido] ben zoyl} 2-methoxyacetanilide oc-{3- [OL-( 2,4-di-tert.-amylphenoxy) acetamido] benzoyl}-2- methoxyacetanilide 4,4-diacetoacetamino) -3 ,3 -dimethyldiphenyl .p,p'-diacetoacetamino diphenylmethane Ethyl-p-b enzoylacetaminobenzenesulfonate Nonyl-p-benzoylacetamin ob enzenesulfon ate N-phenyl-N'- (p-acetoacetaminophenyl) urea n-Propyl-p-benzoylacetaminobenzenesulfonate acetoacetpiperidine w-B enzoylacetpiperidide N w-benzoylacetyl 1 ,2,3 ,4-tetrahydroquinoline N w-benzoylacetyl morpholine In addition to the above couplers, couplers which are particularly useful in color developers include couplers 1-64 listed in columns 3-5 of Spath US. Patent 2,956, 876, issued October 18, 1960. Couplers which are useful in photographic silver halide emulsion layers include couplers 65-77 in column 5 of US. Patent 2,956,876. Other couplers suitable for use in the emulsions of our invention include those described in Spence and Carroll U.S. Patent 2,640,776, issued June 2, 1953; Weissberger et al. U.S. Patent 2,407,210, issued September 3, 1946, and Weissberger et al. US. Patent 2,474,293, issued June 28, 1949.

Any of the conventional color-forming developing agents which have been previously described in the prior art can be used in our invention. The color-forming developers which can be especially useful in our invention include aromatic primary amines containing an amino (substituted or not) or hydroxyl substituent. Phenylenediamines and substituted derivatives thereof containing a primary amino group have been found to provide excellent results in our invention when employed in combination with a balancing developing agent and at least one amine of the type indicated above. Typical of such colorforming developers are the sulfonarnido substituted pphenylenediamines disclosed in Weissberger US. Patent 2,548,574, issued April 10, 1951, the substituted p-phenylenediamines disclosed in Weissberger et al. US. Patent 2,566,271, issued August 28, 1951.

The first developer, i.e., black-and-white negative developer, employed in the process of our invention is generally a rapid developer of the MQ type, i.e., a combination of hydroquinone and Elon developer (p-N-methylaminophenol). Other black-and-white developers, such as hydroquinone alone, pyrazolidone developers (e.g., 1- phenyl 3 pyrazolidone, 4,4-dimethyl-1-phenyl-3-pyrazolidone, etc.) can also be used.

The photographic silver halide emulsions useful in the process of our invention can be prepared according to known methods, such as those described in Hewitson and McClintock US. Patent 2,618,556, issued November 18, 1952, for example. Of course, emulsions prepared by other methods can be used to equal advantage in our invention. These emulsions can be chemically sensitized or not, as mentioned above. Additional chemical sensitizers useful in our invention comprise those disclosed in US. Patent 2,886,437, issued May 12, 1959, in the name of D. E. Piper.

The following examples will serve to illustrate more fully the manner of practicing ourinvention.

Example 1 A portion of a gelatino-silver-bromiodide emulsion which had been sensitized with a sulfur compound and a gold salt as mentioned above, was coated on a cellulose acetate support. The coating was then dried and cut into several strips. One strip of each coating was then exposed for & second to a 500-wattt, 3000 K. light source on an Eastman Type 1b sensitometer. One of the exposed 8 strips was then developed 'for 3 minutes in a "developer having the following composition:

Sodium hexametaphosphate g 0.5 Sodium sulfite (anhydrous) g 40.0 N-methyl-p-aminophenolsulfate g 5.0 Hydroquinone g 2.0 Sodium carbonate (monohydrate) g 25.0 Potassium bromide -.L g 1.0 Potassium iodide (0.1% solution) ccs. 2

Water to make one liter (pH was 10.1 at 70 F.)

The strip was then washed for about 2 minutes.

COLOR DEVELOPMENT The above strip was then given a reversal exposure for about 10 seconds (flash) with a No.- 2 Photoflood set at about 60 inches. The strip was then developed to an adequate D-max. (times-=5 minutes) in a developer having the following formula:

Water to make one liter 1 4-amino-3-methyl-N,N-diethylaniline hydrochloride.

2 2,4-dichloro-5- (p-toluenesulfonamido -1-naphtho1 As hydrochloride.

The strip was then washed for about 10 minutes in water and treated for about 12 minutes in a silver bleach bath having the following composition:

G Potassium ferricyanide Potassium bromide 10 Borax u 7.5 Boric acid 5.0

Water to make one liter The strip was then treated for about 2 minutes in a fixing bath having the composition given below, washed and dried.

. G Sodium thiosulfate (pentahydrate) 200 Sodium sulfite (anhydrous) 10 -Water to make one liter In order to determine the effect of one of the amine aldehyde scavengers, additional strips of emulsion were processed exactly as described above, except that one of the amines, as identified below, in the quantity given, was added to the color developer. The effect of the aldehyde scavenger at the concentration given is shown in the following table:

TABLE Compound No. 00110., gJIiter Etieet Control None Distinct aldehyde odor. 1 (as sulfate) 0.25 No aldehyde odor.

4. 7 Do. 0. 25 Do. 3. 2 Do.

While the above example describes the use of certain of the amines of our invention during cyan development, they can also be employed to advantage in magenta or yellow developers containing appropriate couplers. For example, Compound 1 can also be employed in color developers containing a coupler .for the magenta image, such as Coupler No. 45 of U.S. Patent 2,956,876.

9 Example 2 A multi-layer photographic element of the type described in Mannes et al. US. Patent 2,252,718, issued August 19, 1941, was exposed to an original multi-colored scene and developed for about 3 /2 minutes at 80 F. in a developer having the following composition:

Quadrofos g 0.6 Sodium sulfite g 12.0 p-N-methylaminophenol sulfate g 5.0 Sodium hydroxide g. 1.0 Hydroquinone g 2.0 Sodium sulfite g 6.0 Sodium carbonate g 35.0 Potassium iodide (0.1% solution) rnl 10.0 Sodium bromide g 3.0 Sodium thiocyanate g 1.75

Water to make one liter 1 Sodium tetraphosphate (or hexametaphosphate).

The photographic element was then spray washed with water for about /2 minute and given an exposure to red illumination of 1100 ft. candle seconds. The exposed material was then developed in a cyan developer having the following formula:

Carbohydrazide g 3.2 Quadrofos g 0.7 Sodium bromide g 2.50 Potassium iodide (0.1% solution) ml 5.0 Sodium sulfite g 10.0 Sodium sulfate g 20.0 Sodium hydroxide g 3.30 6-nitrobenzimidazole (1% solution, 1% sodium hydroxide) ml 5.0 p-N-benzylaminophenol g 0.70 Coupler 2 g 1.50 4-amino-N-,N-diethyl-3-metl1ylaniline hydrochloride g 2.60

Water to one liter 1 Sodium tetraphosphate.

2 2- o-acetamido-fi-phenylethyl) 1-11ydr0xy-naphthamide.

As hydrochloride.

In place of the carbohydrazide, it was also found possible to use 4.7 g./liter of semicarbazide, 0.25 g./liter of hdroxylamine sulfate or 0.25 g./liter of hydrazine sulfate.

The photographic element was then washed for about /2 minute with water and exposed to blue light of 300 ft. candle seconds intensity and developed in a yellow color developer containing a phenylenediamine color-developing agent, such as 4-amino-N,N-diethylaniline hydrochloride and a yellow coupler, such as Coupler No. 47 from column 4 of US. Patent 2,956,876. The photographic element was then washed and fogged chemically by treatment with a sodium borohydride solution, as described in Henn et al. US. application Serial No. 699,478, filed November 29, 1957 (now US. Patent 2,984,567, issued May 16, 1961). The photographic element was then developed in a magenta color developer containing a color developing agent, such as 4-amino-N,N-diethyl- 3-methylaniline hydrochloride and a magenta coupler, such as Coupler No. 30 in column 4 of US. Patent 2,956,876.

As indicated above, the amines of our invention are also useful when incorporated into the first or negative developer in a reversal color process. While this first developer produces a black-and-white image, the function of the amine is the same as in the color developer in that it acts as a scavenger of any aldehyde which carries over into the first developer from the prebath containing an aliphatic aldehyde, such as formaldehyde or succinaldehyde. A typical first developer for use in a reversal color process which can be used in our invention is as follows:

G. Quadrofos 1 2.0 p-N-methylaminophenol sulfate 5.0 Sodium sulfite 42.2 Hydroquinone 5.2 Sodium carbonate (anhydrous) 28.2 Sodium thiocyanate 1.38

Potassium iodide 0.005

Sodium bromide 1.7 Sodium bisulfite 1.5 Hydroxylamine sulfate 5.0

Water to 1 liter pH at F. 9.80

1 Sodium tetraphosphate (or hexametaphosphate).

Instead of hydroxylamine sulfate, other amines, such as carbohydrazide, 1.0 g./liter, or any of the other aboveidentified amines can be used. Since only a black-andwhite image is produced in the first developer, it is obvious that the amount of amine stabilizer used is not nearly as important as in the case of the color developers.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

What we claim as our invention and desire secured by Letters Patent of the United States of America is:

1. A photographic developer for producing a color image comprising an aqueous alkaline solution of a pphenylene-diamine photographic developing agent, a p- N-aralkylaminophenol, and a compound selected from the class consisting of (A) a primary amine selected from the class consisting of hydroxylarnine, semicarbazide, hydrazine, carbohydrazide, biuret, aminoguanidine, methylsemicarbazide and water-soluble salts of said compounds, and (B) Girards reagent.

2. A photographic developer for producing a color image comprising an aqueous alkaline solution of a pphenylene-diamine photographic developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and a compound selected from the class consisting of hydroxylamine and a water-soluble salt thereof.

3. A photographic developer for color photography comprising an aqueous alkaline solution of a p-phenylenediamine photographic developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and semicarbazide.

4. A photographic developer for color photography comprising an aqueous alkaline solution of a p-phenylenediamine photographic developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and carbohydrazide.

5. A photographic developer for color photography comprising an aqueous alkaline solution of a p-phenylenediamine photographic developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and a compound selected from the class consisting of hydrazine and a water-soluble salt thereof. a

" 6. In a complete photographic reversal color process wherein a multi-layer photographic element containing a plurality of differentially-sensitized photographic silver halideemulsion layers are given a first exposure, followed by development in a photographic developer for producing a black-and-white negative image and a second exposure, followed by at least one additional development in a photographic developer for producing a colored image, said colored image bearing a complementary relationship to the region of the spectrum to which the photographic silver halide emulsion has been difi'erentially sensitized, the improvement which consists in producing the said colored image by developing in a color developer comprising a p-phenylenediamine developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents and (B) Girards reagent.

7. In a complete photographic reversal color process wherein a multi-layer photographic element containing a plurality of differentially-sensitized photographic silver .halide emulsion layers are given a first exposure, followed by development in a photographic developer for producing a black-and-white negative image and a second exposure, followed by at least one additional development ,in a photographic developer for producing a colored image, said colored image bearing a complementary relationship to the region of the spectrum to which the photographic silver halide emulsion has been differentially sensitized, the improvement which consists in producing .the said colored image by developing in a color developer comprising a p-phenylenediamine developing agent, a balancing developing agent selected from those repre sented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group and a compound selected from the class consisting of hydroxylamine and a water-soluble salt theerof.

8. In a complete photographic reversal color process wherein a multi-layer photographic element containing a plurality of differentially-sensitized photographic silver halide emulsion layers are given a first exposure, followed by development in a photographic developer for producing a black-and-white negative image and a second exposure, followed by at least one additional development in a photographic developer for producing a colored image said colored image bearing a complementary rela- 'tionship to the region of the spectrum to which the photographic silver halide emulsion has been differentially sensitized, the improvement which consists in producing the said colored image by developing in a color developer comprising a p-phenylenediamine developing agent, a balancing developing agent selected from those represented by the following general formula:

R-NHR .wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and semicarbazide,

9. In a complete photographic reversal color process wherein a multi-layer photographic element containing a plurality of ditferentially-sensitized photographic silver halide emulsion layers are given a first exposure, followed 'by development in a photographic developer for producing a black-and-white negative image and a second exposure, followed by at least one additional development in a photographic developer for producing a colored image, said colored image bearing a complementary relationship to the region of the spectrum to which the photographic silver halide emulsion has been differentially sensitized, the improvement which consists in producing the said colored image by developing in a color developer comprising a p-phenylenediamine developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and carbohydrazide.

10. In a complete photographic reversal color process wherein a multi-layer photographic element containing a plurality of differentially-sensitized photographic silver halide emulsion layers are given a first exposure, followed by development in a photographic developer for producing a black-and-white negative image and a second exposure, followed by at least one additional development in a photographic developer for producing a colored image, said colored image bearing a complementary relationship to the region of the spectrum to which the photographic silver halide emulsion has been differentially sensitized, the improvement which consists in producing the said colored image by developing in a color developer comprising a pphenylenediamine developing agent, a balancing developing agent selected from those represented by the following general formula:

wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, and a compound selected from the class consisting of hydrazine and a water-soluble salt thereof.

11. In a complete photographic reversal color process wherein a multi-layer photographic element containing a plurality of differentially-sensitized photographic silver halide emulsion layers is given a first exposure followed by development in a photographic developer for producing a black-and-white negative image and a second exposure followed by at least one additional development in a photographic developer for producing a colored image, said colored image bearing a complementary relationship to the region of the spectrum to which said photographic silver halide emulsion has been diiferentially sensitized, the improvement which consists in producing the said colored image by developing in a color developer comprising a p-phenylenediamine developing agent, a p-N- .benzylaminophenol and a compound selected from the class consisting of (A) a primary amine selected from the class consisting of hydroxylamine, semicarbazide, hydrazine, carbohydrazide, biuret, aminoguanidine, methylsemicarbazide and water-soluble salts of said compounds, and (B) Girards reagent.

12. A photographic developer for color photography comprising an aqueous alkaline solution of a p-phenylenediamine developing agent, a balancing developing agent selected from those represented by the following general formula:

R-NHR wherein R represents an aralkyl group and R represents a p-hydroxyphenyl group, a compound selected from the class consisting of (A) a primary amine selected from the class consisting of hydroxylamine, semicarbazide, hy-

drazine, carbohydrazide, biuret, aminoguanidine, methylsernicarbazide and water-soluble salts of said compounds,

and (B) Girards reagent, and a compound capable of coupling with the oxidation products of said aromatic primary amine developing agent to produce a colored photographic image.

13. A photographic developer for color photography comprising an aqueous alkaline solution of a p-phenylenediamine photographic developing agent, a p-N-aralkylaminophenol, a compound selected from the class consisting of (A) a primary amine selected from the class consisting of hydroxylamine, semicarbazide, hydrazine, carbohydrazide, biuret, aminoguanidine, methylsemicarbazide and water soluble salts of said compounds and (B) Girards reagent, and a phenolic coupler capable of coupling with the oxidation products of said p-phenylenediamine developing agent to produce a cyan image.

References Cited in the file of this patent UNITED STATES PATENTS Albers et al. Jan. 26, 1943 Clarkson et a1 July 18, 1944 Orivelle et a1 May 6, 1947 Vettum et a1. Apr. 15, 1954 Kridel Feb. 24, 1959 Rogers May 9, 1961 FOREIGN PATENTS Great Britain Apr. 2, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Paieni No, 3 141371 July 21 1964 Charlet on C. Bard et all It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column L5 lines 4 to 6 the formula should appear as shown below instead of as in the patent:

H H NNH NH olumn 3. l1ne 65 for "2 100 032" read 2 400532 column I 11110 23 after "amylphenoxy" 1nser't a closing parenthesis; column 7 i 1 me 74. for "SOO-wattt" read SOD-watt column 8 1111s 30 for "12'' read 2 Signed and sealed this 8th day of December 1964., (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Alicsting Officer Commissioner of Patents 

1. A PHOTOGRAPHIC DEVELOPER FOR PRODUCING A COLOR IMAGE COMPRISING AN AQUEOUS ALKALINE SOLUTION OF A PPHENYLENE-DIAMINE PHOTOGRAPHIC DEVELOPING AGENT, A PN-ARALKYLAMINOPHENOL, AND A COMPOUND SELECTED FROM THE CLASS CONSISTING OF (A) A PRIMARY AMINE SELECTED FROM THE CLASS CONSISTING OF HYDROXYLAMINE, SEMICARBAZIDE, HYDRAZINE, CARBOHYDRAZIDE, BIURET, AMINOGUANIDINE, METHYLSEMICARBAZIDE AND WATER-SOLUBLE SALTS OF SAID COMPOUNDS, AND (B) GIRARD''S REAGENT. 